1. Field of the Invention
The present invention relates to a fire hydrant locking arrangement which is intended for utilization on a conventional fire hydrant. Moreover, the present invention also relates to a novel and unique method of producing a fire hydrant locking arrangement which will inhibit the unauthorized opening of fire hydrants while facilitating the ready servicing of the internal components of the fire hydrant.
In many geographical areas, and especially in sizeable towns and cities, serious problems have been encountered as a consequence of the unauthorized and possibly unlawful opening of fire hydrants. Ordinarily, fire hydrants each include an upstanding pipe or standpipe closed at the upper end by a bonnet. The standpipe is usually equipped with a water discharge connection (normally for attaching a fire hose) in its circumferential wall, which is maintained in a plugged condition, and a valve in the lower end of the standpipe communicates with a water main below ground, which valve is actuated by suitable rotation of a valve stem extending upwardly through the bonnet of the fire hydrant, in order to control the flow of water through the fire hydrant to the discharge connection. The valve stem is generally equipped with a polygonally-sided portion at its upper protruding end, which may be rotated through the manipulation of a suitable tool when coupled thereto, such as a wrench, in order to open the valve and initiate (or conversely to close the valve and inhibit) a flow of water from the fire hydrant through the water discharge connection. During the normally hot and sweltering summer months encountered in many locales, fire hydrants are frequently unauthorizedly opened by children and adults and a flow of water initiated to provide a cooling effect in that the water is permitted to spray and/or flow into the street so as to enable bathing or immersion therein and to run off along gutters into sewers or the like. However, when an appreciable number of fire hydrants are simultaneously opened in any particular locale, the water pressure in that area may tend to fall off to such a low level as to prevent adequate water pressure from being available should an emergency arise, such as a fire necessitating the use of fire hoses to douse the conflagration. Moreover, the excessive use of water in geographic areas which are subject to drought conditions requires that the frequently limited stored supply of water be safeguarded at all times from any unauthorized depletion.
In order to prevent the unauthorized and/or unlawful opening of fire hydrants, provision has been made heretofore to uncouple the upper protruding end of the hydrant post or stem from the valve actuating mechanism which is contained within the body or standpipe of the fire hydrant, and to operatively connect these components through the use of suitable special tools when it is desired to actuate the waterflow valve; for example, through the use of magnetic wrenches or the like which are not readily accessible to the general public. Other types of constructions contemplate equipping the upper end of the post or valve stem which extends from the bonnet on the fire hydrant with superimposed cylindrical members, of which one is secured to the post and another encompasses the first-mentioned cylindrical member so as to be rotatable relative thereto, and which will prevent any unauthorized rotation of the post and actuation of the fire hydrant valve without the utilization of a specialized tool with one of the relatively rotatable cylindrical members.
2. Discussion of the Prior Art
Among various patents which disclose operating mechanisms for actuating fire hydrant valves or the like in order to control the flow of water from the fire hydrants, and in which the mechanism is mounted on the upper ends of fire hydrant valve stems projecting from the bonnets of the fire hydrants, and which include relatively rotatable cylindrical members protectively encompassing the post, consideration must be given to Kopesky U.S. Pat. No. 4,620,428. In that instance, the lock and coupling apparatus for securing fire hydrants against unauthorized opening thereof, includes an inner cylindrical member which is fixedly connected to a post so as to be secured against relative rotation therewith, and whereby an outer cylindrical member encompassing the upper end of the post for the valve and the inner cylinder which is fastened to the post, is essentially connected to the inner cylindrical member so as to be rotatable relative thereto but secured against axial displacement and separation therefrom. Consequently, the application of a rotational moment or torque to the outer cylindrical member will not be transmitted to the inner cylindrical member and to the therewith secured post, thereby inhibiting actuation of the fire hydrant valve, until such time as an appropriate tool designed for this purpose is employed with the outer cylindrical member, such as a tool which may be in the form of a wrench incorporating a magnet adapted to attract a passive magnetic locking member for securing the outer and inner cylindrical members against relative rotation, and thereby enabling actuation of the valve post for controlling the valve and, resultingly, the flow of water from the fire hydrant. The outer and inner cylindrical members are coupled with each other through the intermediary of either a plastic or possibly metallic snap ring engaging in cooperating grooves formed in facing circumferential surfaces of the cylindrical members; and in order to be able to separate the cylindrical members, such as for gaining access to the interior of the fire hydrant, a considerable axial force has to be exerted to the outer cylindrical member to shear through the snap ring. This may result in extensive damage to the grooves in the ring members, and possibly render the latter unusable for subsequent applications, entailing considerable replacement or machining expenditures.
Camp U.S. Pat. No. 4,716,922 discloses a magnetic fire hydrant guard in which a ring member is fastened to an upstanding valve-actuating post of a fire hydrant through the intermediary of a radially extending locking screw, and with an outer ring member being positioned thereover and fastened thereto. This fails to provide the appropriate protection against tampering with the operating structure of the fire hydrant by an unauthorized person as contemplated by the present invention.
McMurray U.S. Pat. No. 3,840,041 discloses a magnetic lock and wrench structure for fire hydrants, wherein an outer ring member is adapted to encompass an internal ring member which is fastened a post employed for actuating a fire hydrant valve. There is no disclosure of a locking arrangement between the outer and inner cylindrical ring members or cylinders adapted to prevent axial separation while concurrently allowing for relative rotation between the members.
Hurd U.S. Pat. No. 4,336,698 relates to a lock for a lug nut in which an outer sleeve is relatively rotatable with respect to an inner sleeve received therein which provides a threaded connection with a bolt lock assembly, and which prevents axial separation therebetween unless a shearing action is applied thereto, possible resulting in extensive damage to the components.
From the foregoing, although fire hydrant guard structures in the form of various kinds of locks and cylindrical coupling members which are attached to the upper end of the first hydrant valve-actuating post are known in the technology, while being interconnected for relative rotation although axially secured, these structures normally employ metal rings, such as steel snap rings or the like, which must be sheared through with the application of considerable forces generating high stresses in order to allow for the separation between the cylindrical members, thereby frequently resulting in damage to the various components requiring either extensive remachining or reworking thereof, or even rendering these completely unusable for further service, and making these structures extremely expensive to service and/or replace.